80cu Tank at 800 Feet ????

[Akimbo]

Thanks for explaining all this, Akimbo!

I have lurked the "Commercial Divers" a little, but you seem to speak your own language in there. Thanks for the basic-diver version.

The industry sure went through some horrific accidents in their learning curve.

BTW - there's a story running around the Internet about 'a bad day at work' where a diver talks about water being pumped into his suit. There began an itching, then stinging feeling, and he realized that the pump had sucked up a jellyfish and the tentacles were being blown down his back and buttocks.

Is that true? Seems like you'd have a better filter on your pump.

We do have better filters... now.

I have heard the story too, but never heard any names or job sites. It could be true or just derived from warnings that DUI (Diving Unlimited then) put in a manual. I am interested to know that answer too.

Have you heard these old deep sea rig (Hard-Hat) accidents/sea stories?

This link includes links the Myth Busters videos.
http://www.scubaboard.com/forums/commercial-divers/333195-deadly-helmet-squeeze.html

Quoted from:
http://www.scubaboard.com/forums/co...using-bc-ssa-commercial-work.html#post5213856

... Most of you guys have probably heard this story, but nobody seems to know where, when, or who... where is myth busters when you need them? Anyway, this guy in heavy gear wraps his arms around some 200 Lb piece on the bottom and inflates his suit. He is walking it over the bottom, looses his footing, and drops it. He shoots to the surface like a Polaris missile, his suit bursts just as he breaches the surface, and falls back to the bottom like anchor chain.

For guys who don't know heavy gear, here is why the story is plausible. Arm cuffs on heavy gear are really tough molded rubber, not like the wimpy latex used on dry suits today. They can hold a seal tight enough to inflate the suit so stiff that you can't bend your arms and float like a Zodiac.

Old suits were expensive, made from cotton canvas over rubber, and were retired when they were so rotted they wouldn't hold any more patches. Also, the exhaust valve is nowhere near big enough to vent the suit on an explosive ascent. The exhaust valve is basically an adjustable relief valve you set for enough back pressure so the suit is comfortable in terms of squeeze and buoyancy. There is a chin button to override the exhaust valve and dump air. It can also be pulled shut with your mouth to inflate the suit.

So, is this one of those "don't screw up" stories from diving school or did it really happen?

Here is a new accident that could relate to tech divers in confined spaces:
http://www.scubaboard.com/forums/commercial-divers/336809-diver-harness-cross-chest-hazard.html

 

[Akimbo]

I just thought of a gas planning "trick" saturation divers can get away with and illustrates some diving physics to those who never had any reason to think about it. Remember the usable gas calculation? Pressure in tank minus bottom pressure minus first stage IP

We get to cheat on bailout bottles. There is a charging whip in the transfer chamber the bell mates to. We top our bailouts off when we reach holding or saturation depth so it is the max pressure the cylinder allows as read at depth, or over bottom pressure. The tank sees the same differential pressure as it would on the surface, but can hold 445 PSI more surface equivalent gauge pressure at 1000', for example.

Sure some teams have forgotten to bleed the pressure down before decompression. Yep, the blow-out disks pop and scare the crap out of everyone. Nothing like loud and unexpected rushing gas noises to put divers in chambers on high alert instantly.

 

[Jax]

I just thought of a gas planning "trick" saturation divers can get away with and illustrates some diving physics to those who never had any reason to think about it. Remember the usable gas calculation? Pressure in tank minus bottom pressure minus first stage IP

We get to cheat on bailout bottles. There is a charging whip in the transfer chamber the bell mates to. We top our bailouts off when we reach holding or saturation depth so it is the max pressure the cylinder allows as read at depth, or over bottom pressure. The tank sees the same differential pressure as it would on the surface, but can hold 445 PSI more surface equivalent gauge pressure at 1000', for example.

Sure some teams have forgotten to bleed the pressure down before decompression. Yep, the blow-out disks pop and scare the crap out of everyone. Nothing like loud and unexpected rushing gas noises to put divers in chambers on high alert instantly.

That's what you get for cheating!

So, do you dive much recreationally, or do you get so much at work you'd rather stay dry?

 

[Akimbo]

That's what you get for cheating!

So, do you dive much recreationally, or do you get so much at work you'd rather stay dry?

I don't dive for the oil business anymore, to the great relief of my bride. I occasionally get involved in some special projects, like deep water salvage... treasure hunts really. I evolved into design, consulting, manufacturing, and project management. There is still nothing like dropping out that hatch though; even if it is only on testing, training, or evaluation dives. However, I don't miss the lifestyle.

Since moving up to the land of Red Abalone about 7 years ago, I am doing more freediving than ever. For the first time in my life I have the freedom, time, and proximity to look out the window and drive a few minutes to get in the water. I Scuba mostly in Monterey. It is amazing how enjoyable freediving is to me after being engulfed in massively complex operations, dragging umbilicals, having crap hanging everywhere, and dealing with large support crews. Maybe that is one reason I enjoy Solo so much.

It seams like there are two divisions of commercial divers, those that dive because they love being in the water and others for the challenge (and money). A friend that skippers a dive boat in Monterey relates a story of a retired Navy SEAL. The conversation goes something like this:

Captain: Do you want to make a jump? (they are offshore on his boat)

SEAL: Is there something down there that needs to blow up or die?

Captain: Not really

SEAL: Then why would I want to get wet?​

The story is humorous and illustrative. My younger brother was a commercial diver in the late 70s/early 80s and has the same perspective, except he wants to fix or salvage something.


BTW, cheating is exactly what you want to do if it gives you a few more seconds to get your head back in the hatch on bailout.

 

[ianr33]

BTW - there's a story running around the Internet about 'a bad day at work' where a diver talks about water being pumped into his suit. There began an itching, then stinging feeling, and he realized that the pump had sucked up a jellyfish and the tentacles were being blown down his back and buttocks.

Is that true? Seems like you'd have a better filter on your pump.

Probably not

snopes.com: Jellyfish in Wetsuit

 

[speedyal]

What if it was a 6'6" gay jelly fish named bubba id hate to be locked up with that guy

 

[Jax]

What if it was a 6'6" gay jelly fish named bubba id hate to be locked up with that guy

:w-t-f: And this has what to do with deep diving?

 

[Cave Diver]

:w-t-f: And this has what to do with deep diving?

Where else would you expect to find a 6'6'' jelly fish? At the surface???

 

[Jax]

M m m mm Japan? Aren't they sinking the fishing ships?

They're close to the surface, though . . .

http://www.foxnews.com/scitech/2009/11/02/enormous-jellyfish-sink-japanese-fishing-boat/

 

[Cave Diver]

M m m mm Japan? Aren't they sinking the fishing ships?

I think that was Godzilla.